This invention generally relates to a clutch drum for use in vehicle transmissions and a method of manufacturing the clutch drum.
Vehicle transmissions typically include a clutch for engaging an engine output shaft to the gear box of the transmission. Typical clutches include a series of clutch plates that are housed within a clutch drum. A variety of clutch drums are known. One feature of most clutch drums is the use of a snap ring to maintain the clutch plates within the clutch drum while also allowing the clutch plates to be moved axially within the clutch drum as needed.
A variety of attempts at making clutch drums that include snap rings have been used. In most arrangements, the clutch drum includes a series of splines defined by interspaced inward and outward projections on the clutch drum. A snap ring groove is typically provided by punching through the inwardly protruding spline portions to thereby break the continuity of the spline and form a groove to receive the snap ring. In order to complete a clutch drum with such an arrangement, an outer housing portion must be attached to provide a smooth outer surface that is adapted to receive a brake band.
While the known arrangements have proven useful, they are not without disadvantages and shortcomings. One problem associated with typical clutch drums is that forming the groove to receive the snap ring results in weakening the material in the area of the groove so that the clutch drum may fail under certain conditions. Another problem is that requiring a separate outer housing introduces additional material and manufacturing processes and time.
Accordingly, it is desirable to provide a clutch drum having better strength characteristics than has been achieved in the prior art. Further, it is desirable to provide a clutch drum that can be manufactured more economically. This invention addresses both of those needs.